1. Field of the Invention
The present invention relates to a card reader, which reads information from a card shaped recording medium, hereinafter, referred to as a card shaped medium, provided with an information recording part or information recording means, such as a magnetic stripe or an IC chip. More specifically, the present invention relates to a card reader provided with a function that prevents a card shaped medium from being stolen with fraudulent conduct by a malicious person, such as a criminal.
2. Description of Related Art
A card reader that is equipped in an ATM device (Automated-Teller Machine) or a vending machine is a device that commonly performs reading and writing of information from and on a card shaped medium inserted from a card insertion port. In such a conventional card reader, a protection shutter is provided at an inner side of the card insertion port to prevent a foreign object other than the card shaped medium from being inserted from the card insertion port or to prevent the card shaped medium from being taken out and stolen with fraudulent conduct by a malicious person, such as a criminal. The protection shutter is moved to open when a medium detection sensor detects a card shaped medium, which is inserted from the card insertion port, and moved to close when the card shaped medium has detected that the medium has been taken into the inside of the device from the card insertion port. Fraudulent conduct by a criminal may be conceived as follows. For example, immediately after a customer inserts a card shaped medium into a card insertion port, a failure may occur in mechanical components or in an electric system inside of the device to cause the card shaped medium to be jammed and/or abnormally stopped. Alternatively, a criminal may intentionally conduct a malicious act to cause the card shaped medium to be compulsively stopped. In these cases, when the customer departs from the place to call a person in charge under the state where the protection shutter is opened, the criminal can take out the card shaped medium at that time.
In order to prevent such a fraudulent theft of a card shaped medium, some prior attempts have been proposed. For example, one attempt is that a card shaped medium, which is abnormally stopped, is locked by a member whose tip end is sharp and is stuck into its card face at the abnormally stopped position so as not to be illegally pulled out. (See, for example, Japanese Patent Laid-Open No. 2001-222686). Further, another attempt for preventing a fraudulent theft of a card shaped medium has been known in which the illegal taking-out of the card shaped medium by a criminal is prevented by pressing a pawl of a ratchet structure on the surface of the card shaped medium.
In addition, another attempt has been known in which an eccentric cam is used to prevent the illegal taking-out of a card shaped medium. In this attempt, the eccentric cam provided at a card insertion port is rotated around a rotation shaft as a center and the outer peripheral face of the eccentric cam comes into contact with the surface of the card shaped medium. The outer peripheral face of the eccentric cam with a prescribed thickness is formed in a saw tooth shape, and the taking-out of the card shaped medium from the card insertion port is prevented by a frictional force when the outer peripheral face is brought into contact with the card shaped medium. In addition, when the card shaped medium is going to be taken out from the card insertion port, the eccentric cam turns by a frictional force between the card shaped medium and the eccentric cam, and the outer peripheral face is tightly brought into contact with the card shaped medium to prevent the taking-out of the card shaped medium. (See, for example, Japanese Patent Laid-Open No. 2005-56376).
However, in the card reader described in the former attempt, further improvement is required. In the former attempt, a sharp-pointed member is stuck into the card shaped medium. Therefore, an improvement is required to cope with the situation even when a criminal tries to take out the card shaped medium with a pulling-out force stronger than the locking force by the sharp-pointed member to thereby the card shaped medium at the stopped position. Further, the card locking device described in the former attempt is required to be disposed near the card insertion port, and its disposing space causes the size of the card reader to be larger.
Further, in the card reader described in the latter attempt, since the eccentric cam made of one piece of plate is used, the card may be torn to be carried away when the card is forcibly taken out. In particular, a card shaped medium of recent years may be structured as a composite type in which a magnetic stripe and an IC chip are mounted. Thus, even when one of the magnetic stripe and the IC chip is damaged, the other information may be read.
In addition, in the card reader described in the former attempt in which a locking pawl is engaged with the surface of the card shaped medium to prevent illegal taking-out of the card shaped medium, a locking force by the locking pawl is effectively applied when a criminal applies force to the card shaped medium in its taking-out direction. Similarly, in the card reader described in the latter attempt, the eccentric cam is tightly brought into contact with the card shaped medium to prevent illegal taking-out of the card shaped medium. However, in the above-mentioned card readers, when a criminal applies a force that pushes the card shaped medium in the reverse direction and obstinately tries to repeat pushing and pulling of the card shaped medium to perform illegal taking-out of the card shaped medium, the locking pawl is unable to apply a locking force against the pushing force in the reverse direction.